Electrical connecting device



March 17, 1931. cw. wYMAN ELECTRICAL CONNECTING DEVICE Filed' April 28, 1927 2 Sheets-Sheet l MAM.

March 17, 1931. C. W. WYMAN 1,796,418

ELECTRICAL CONNECTING DEVI CE Filed April 28, 1927 2 sheets-Sheet 2 @if A W Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE CHARLES W. WYMAN, OF CLAREMONT, NEW HAMPSHIRE, .ASSIGNOR TO SULLIVAN MA- CHINERY COMPANY, A CORPORATION OF MASSACHUSETTS ELECTRICAL CONNECTING DEVICE Application filed April 28,

This invention relates to electrical apparatus and more particularly from one aspect to connector devices and from another aspect to grounding systems for use with coal mining machines.

One of the objects of the invention is to provide an improved grounding system for mining machines. Another object of the invention is to provide an improved grounding system for mining machines wherein the latter are grounded in the main entry and to thc transport truck in an improved manner. Still another object of this invention is to provide improved connector devices which may be carried at the entry and on the transport truck whereby the motor of the machine may be supplied with electric current and the machine grounded while cutting on the mine bottom or while running about the mine on its transport truck. A further object of the invention is to provide an improved interlocking connector mechanism ofgeneral application. These and other objects of the invention Awill subsequently more fully appear.

In the accompanying drawings in which I have shown for purposes of' illustration one form which my invention may assume in practice,

Fig. 1 is a somewhat diagrammatic view illustrating the improved grounding system incorporated in a complete cutting and transport apparatus.

Fig. 2 is in the main a central longitudinal vertical section taken through one of the improved plug connections, but a portion at the lower left hand side of the figure is broken back to an angular plane to the rear of the central plane.

Fig. 3 is a transverse vertical sectional View taken on the line 3 3 of Fig. 2.

Fig. 4 is a transverse vertical sectional View taken on the line 1 -4 of Fig. 2.

Fig. 5 is a transverse vertical sectional View taken on the line 5-5 of Fig. 2.

In the illustrative embodiment of my invention I have shown a main entry 1 of a mine from which a room 2 projects off laterally, the entry 1 being equipped with the usual 'trackway 3 while the room 2 is provided with a trackway 4, all in a well known 1927. Serial No. 187,399.

manner. Extending along the side of the entry 1 is the usual trolley line 5 and the usual water pipe 6. As clearly shown in Fig. 1 disposed on the traclway 3 of. the room 2 is a usual mining machine transport truck 5 7 while disposed on the mine bottom adjacent the working face of the room is a usual coal cutting machine 8 herein of a familiar electric room and pillar type.

Secured to a usual roof prop 9 is a junction or connection box generally designated 10. The junction box 10is made up of a number of different elements as will subsequently appear. The central element of the box 10 is formed by a central rectangular block 11 of insulating material and this is adapted to be secured by transverse holding elements 12 to the roof prop 9. The block 11 has a central opening 13 within which is rotatably mounted a cylindrical insulating block 14 having secured to one end thereof a thin plate of insulating material 14a whose purpose is later described. The members 14, 141a are held in position relative to the central block 11 by means of hollow end members 15, 16 which have enlarged recesses 17 at their adjacent ends within which the ends of the composite member formed of the elements 14 and 111a extend. The outer ends of thc members 15 and 16 respectively carry end plates 18 and 19. The end plates 18 and 19 and the members 15 and 16 are clampedto the central block 11 by means of longitudinally extending tie bolts 20. The block 15 is provided with a bore 15a communicating with the larger recess 17, which leaves a shoulder 15b at its junction with the bore 17 to cooperate with the block 14. Three cylindrical bores 15c extend longitudinally from the bore 15a throughout the length of the block 15 and are arranged at the corners of an equilateral right prism whose edges are equidistant from the axis of the cylindricall member 15. Asillustrated, the rotatable insulating block 14 has suitably secured thereto projecting fingers 21, herein three in number, each extending into one of the recesses 15E. The plate 18 is traversed by openings each coaxial with one of the bores 15, two of these openings being comparatively small and one of the full diameter of one of the chambers 15C. The large opening is designated 18a, the two smaller openings 18b. A spring socket contact 22 carried Within a detachable plug 23 and constituting the terminal power connection is adapted to cooperate with the finger 21 in the recess 15c with which the opening 18a is in alinement. The handle 23 is :1t-the end of a -wire 24 which is connected tothe spring Contact` member 22 at its end which enters the handle. The other end of this wire is suitably connected with a trolley fuse generally designated 25 which is connected in any suitable manner with the trolleywire 5. The other fingers 21 which-extend into the chambers 15c with which communication is had through the openings 18b are respectively connected as at 26 to wires 28 and 29, the wire 28 having a return ground connection with one of the track rails while the wire 29 is clamped to the water pipe 6 and forms a ground connection for the machine.

The insulating member 14 is provided with a series of chambers 14b to which access is had through openings 14 in the plate 14a. These chambers are in alinement with the fingers 21 and contain spring socket contacts 30 which are in alinement with and in electrical connection with the fingers 21. Fingers 31 are carried by a detachable plug 32; The plug 32 is preferably composed ,of two parts 33, 34 suitably held together by bolts 35. Connected to the fingers 31 are lead wires 36, 37, 38 which are electrically connected to the wires 24, 28 and 29 respectively when the fingers 31 lie Within the resilient socket contacts 30, and Ythejwire's 36, 37, 38 are en-y closed within the conductor cable 39.I The openings 14c permit the passage with a very small clearance of the fingers 31. i

It is undesirable for the connector plug 32 to be in-serted or withdrawn while the socket member 22 is connected to the finger 21. These operations are precluded by means which causes the positioning of the contacts been inserted through the recesses 41 andthe plug rotated as is permitted by the provision of arcuate recesses 42 in the member 15 in communication with the notches 41, the plug 23 cannot be withdrawn and it can be withdrawn only by rotating it back to a position in which the ends of the pin 40 come into register with the openings or notches 41.

To lock the plug 32 within the junction box it is provided With a radially extending pin 43 which may be inserted in a predetermined relation of the parts through a longitudinally extending notch 44 formed in the member 16 to such a distance that it comes opposite an arcuate recess 45 into which the pin 43 may be moved by rotation of the member 34. Vhen the pin 43 is in alinement or registers with the longitudinal notch 44 it may be moved therethrough and the plug 32 may be inserted or withdrawn as the case may be. lVhen, however, the pin 43 has been turned until it is engaged within the arcuate recess 45, the member 32 is locked in place. 4

A very important feature must now be noted. The pin 43 is so related to the plug 32 and the notch 44 to the chambers 15c andopening 18a that when the pin 43 is in registry with the notch 44 and the connector fingers 31 Within the connectors 30, the fingers 21 are disposed distinctly eccentrically within the chambers 15, while when the plug 32 is rotated to bring the pin 43 substantially to the end of the arcuate notch or recess 45 the fingers 21 are moved to 'a position coaxial with the chambers 15 As a result of thisv it will be evident that the connector mem# ber 23 can be positioned to fit its socket over the finger 21 only when the connector plug 32 has been inserted and turned to bring the fingers 21 into coaxial relation to the chambers 15C, or when with the connector member 32 withdrawn the member 14 is rotated to bring the finger 21 into coaxial relation with its chamber15C and orifices 18a. Now it should be noted that should the connector 23 be applied and the circuit closed by connection of the fingers'21, 22 as a result of tampering with the device and turning the member 14 to make this possible, no possible chance of inserting the connector plug 32 or establishing any current flow in its wires will exist. This will be obvious for the reason that until the pin 43 enters the slot 44 the fingers 31 cannot reach the contacts 30 so'that even though the fingers may come into alinement with the sockets no circuit can be established, and if the pin is moved into the socket the fingers 31 will simply abut against the imperforate portions of the plate 14a as the openings 14c in these plates will lie out of alinement with the fingers 31 when the pin 43 is in the slot.

'In the normal mode of use of the plug and connector the plug will be inserted in the member 16, the pin 43 moving down the slot 44 into the same transverse plane as the arcuate recess 45. The plug 32 will thenbe rotated,turning with it the member 14 and as the pin 43 passes into the arcuate recess 45 plug 32 can no longer be withdrawn.V When the pin reaches the end of the arcuate recess the finger 21 will have been moved into a coaxial relation with the-opening 18a and the connector member 23 can then be placed in v position and rotated to lock it in place. Ob-

viously the connector 23 must be withdrawn before the plug 32 can be turned in the opposite direction to permit its Withdrawal and accordingly a grounding circuit will inevitably be completed Whenever current How to the truck can take place.

As shown in Figs. 1 and 2 the conductor cable 39 is adapted to be .Wound on the cable reel 46 suitablyl rotatably mounted on the rear end of the transport truck 7. The Wire 36 in the cable 39 Which receives current from the trolleywire 5 through the Wire 24 is connected through slip ringv connections, not shown, and a terminal plugto awire 49 which is enclosed Within a conductorcable 50, the Wire 49 being adapted to supply current to the windings of the motor of the mining machine v8. Also enclosed within the conductor cable 50 is a return Wire 51 connected through a terminal plug 52 and suitable slip ring connections, not show-n, vto the return Wire 37 Within the conductor cable 39, the return Wire 37 being connected to one of the track rails p through the Wire 28. The ground wire 38 within the cable-39, which is connected to the Wire 29 grounded on the water pipe 6, is clamped to and grounded on the reel shaft. The Wire 54 enclosed within thecable 50 is grounded on the casing of the terminal plug 52 While the other end ofthe Wire 54 is ground-` edY on the machine frame of the mining machine 8. As clearly shown in Fig. l, suitably secured to the side of the truck 7 is a junction or connection box 57 Which is identical in structure to the junction box 10 heretofore described.

When it is desired to transport the machine 8 about the mine on its transport truck 7 the operator rotates the plug 23, unlocking the same and then removes the plug from the punction box 10. The plug 23 is then inserted Within the junction box 57 on the truck. The operator then unlocks the plug `32 and removes the same from the junction box l0 and the plug is thereafter inserted Within the junction box 57. l When the plugs 23 and 32 are positioned and locked Within the junction box 5.7, the return Wire 37 Within the cable 39 and the groundv wire 3 8 are grounded t0 the side of the truck frame, as at 58, by means of Wires 59 and 60 respectively. The operator then disconnects the trolley fuse 25 from the trolley wire 5 and holds the fuse in his hand in contact With the trolley Wire, thus supplying current to the mining machine motor as As a result of my improved grounding systern for mining machines, it will be noted that the mining machine is grounded in an improved manner both during the cutting operation and when the machine is travelin about the mine on its transport truck. t will further be noted that by the use of my improved grqunding system all possibility of the operator or his helper receiving shocks, due to an insuicient -ground connection is eliminated. These and other advantages of my improved grounding system will be clearly apparent to those skilled in this art.

While I have in this application speciiically described one form` which my invention may assume in practice, it Will be understood that vthis form ofthe same is shown for purposes of illustration and that the 1invention may be modified and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is l. In an electrical apparatus, a connector device comprising a casing, a member movably mounted therein and carrying a plurality of contacts a connector plug insertable in said casing on one side of said member and having contacts to engage certain of said first mentioned contacts, cooperating means on said plug and casing for preventing insertion of said plug in certain relative positions of said plug and casing, a cooperating contact carrying n.ember insertableinto said casing and having a contact to engage one of said first mentioned contacts after insertion, and

means provided by said casing for preventing said first mentioned contacts, the spacing of said contacts with respect to the spacing of the openings necessitating movement of one of said first mentioned contacts by its cooperating contact after connection is made in order that the other cooperating contact can b'e inserted. f

3. In an electrical apparatusa casing having therein a rotatably mounted Contact carrier having contacts thereon, said casing having openings through which access may be had to said contacts, cooperating contacts insertable through said openings, and means for preventing insertion of one of said cooperatning contacts until after the other has been inserted and said contact carrier rotated to another position.

4. In an electrical apparatus, a' casing having therein ya. rotatably mounted contact carrier having contacts thereon, said casing having openings through which access may be had to said contacts, cooperating contacts insertable through said openings, and means for preventing insertion of one of said cooperating contacts While the other is being inserted including means for maintaining one of said first mentioned contacts in a position offset from the axial line of its associated opening.

5. In an electrical apparatus, a casing having openings at its oppositecends through Which connector terminals may be inserted, the axes of said openings being disposed out of alinement With each other, movably supported contacts in said casing accessible through said openings, terminals connectible With said contacts, one of said contacts being movable into and out of alinement with one of said openings, and means preventing connection of one of the terminals with the other contact except When said first mentioned contact is out of alinement With its opening.

6. In an electrical apparatus, a casing hav- Aing openings at its opposite ends through which connector terminals may be inserted, the axes of said openings beingvdisposed out of alinement with each other, movably supported contacts in said casing .accessible through said openings, terminals connectible wlth said contacts, one of said contacts 'being movable into and out of alinement with one o f said openings, and means preventing connection of one of the terminals with the other contact except when said first mentioned contact is out of alinement with its opening, said contacts being movable after said terminal is connected to its having openings at its opposite ends through which connector terminals may be inserted,

the axes of said openings being disposed out,

of alinement with each other, movably supported contacts in said casing accessible throu h said openings, terminals connectible with said contacts, one of said contacts being movable into and out of alinement with one of said openings, means preventing connection of one of the terminals With the othercontact except when said first mentioned contact is' out of alinement With its opening, said contacts being movable after said terminal is connected to its contact to a position Where said first mentioned contact is alined with its opening thereby permitting its connection with the other terminal, and means operative upon such movement for locking said terminal against direct Withdrawal from the casing.

8. In an electrical apparatus, a casing, a.

contact carrier rotatable th'erein, alined contacts on said carrler Whose axls of allnement is parallel to but offset from the axis of rotation of the carrier, said casing having an opening Whose axis lies' in the surface of revolution in which the movement of said contacts takes place, a connector device having a contact adapted to cooperate with one of said first mentioned contacts insertable'in said opening, said casing having a second opening in which a second connector device lution in which the movement of said contacts takes place, a connector device having a contact adapted to cooperate With one of said first mentioned contacts insertable in said opening, said casing having a second opening in which a second connector device may be inserted to cooperate With the other of said alined contacts, and means precluding insertion of said second connector device except When said alined contacts are in a position offset laterally from the axis of said first mentioned contact device receiving opening, said casing and second connector device being further provided with means cooperating to permit rotation of said second connector device and with it said alined contacts to position the latter in alinement with the axis of the opening to receive the first mentioned connector device.

10.In an electrical apparatus, a casing, a Contact carrier Arotatable therein, alined cont-acts on said carrier Whose axis of alinement is parallel to but'offset from the axis of rotation of the carrier, said casing having an openingvvhose axis lies in the surface of revolution in which the movement of said contacts takes place, a connector device having a contact adapted to cooperate With one of said first mentioned contacts insertable in said opening, said casing having a second opening in Which a second connector device may be inserted to cooperate With the other of said alined contacts, and means precluding insertion of said second connector device except when said alined contacts are in a. position offset laterally from the axis of said first mentioned contact device receiving opening, said casing and second connector device being further provided with means cooperating to permit rotation of said second con-l nector device and With it said alined contacts to position the latter in alinementwith the axis of the opening to receive the first mentioned connector device, said last mentioned means acting to lock said second connector device against direct Withdrawal.

11. In an electrical apparatus, a casing, a contact carrier rotatable therein, alined contacts on said carrier the axis of alinement of said contacts being substantially parallel to but offset from the axis of rotation of the carrier, said casing having an opening Whose axis lies in the surface of rotation in which the movement of said contacts takes place, a connector device having a contact adapted to'cooperate with one of said first mentioned contacts insertable in said openin said casing having a second opening in w ich a second connector device may be inserted to cooperate With the otherlof said alined contacts, and means precluding insertion of said second connector device except when said alined contacts are in a position oifset laterallyfrom the axis of said first mentioned Contact device receiving opening, said casing and tation'of said second connector device and with it said alined contacts to position the latter in alinement with the axis of the opening to receive the rst connector device, said last mentioned means actingr to lock said second connector device against direct withdrawal until reverse rotation takes place and said first mentioned connector device and said casing being provided with means adapted to cooperate to lock said first mentioned connector device a ainst direct withdravval after connectionA etween the same and its cooperating alined contacts is iestablished.

In testimony whereof I aix m si ature. CHARLES W. MAN. 

